【作者】 赵金霞；

【导师】 王杰德；

【作者基本信息】 武汉理工大学 ， 结构工程， 2003， 硕士

【摘要】 基于可靠性的结构智能化优化设计是近十几年来发展起来的一门新兴学科。它将结构作为一个整体考虑，并且研究了结构在未来工作期间表现的随机性，比传统的结构优化设计更为合理。将进化算法等智能化方法运用于结构可靠性优化设计，是当前该领域内研究的一个热点。 本文首先介绍了基于可靠性的结构智能化优化设计及其分析方法的发展概况，接着简要地叙述了结构系统可靠性计算的基本理论和本文采用的方法。文中在可靠性分析和计算部分，考虑空间刚桁架结构系统的失效演化历程，采用基于系统临界强度的约界准则和约界算法，将柔性自适应控制边界引入失效模式识别过程；同时，用荷载增量法和微分等价递归算法相结合，确保在严格不遗漏主要失效模式的情况下，快速准确地求解失效模式的极限状态方程和可靠度指标。在此基础上，编制了适用于大中型结构自动化可靠性分析的程序，给出了相应的验证分析算例。文中还对结构体系可靠性分析理论和算法中的相关问题进行了深入地探讨，得出了一些结论。实践证明，本方法是可行且有效的。 由于问题的复杂性和常规算法的局限性，计算智能应运而生。遗传算法是目前在解决优化问题中国内外尝试较多、效果较好的一种启发式随机优化智能方法，所以本文的主要任务就是开发一个基于遗传算法的结构系统可靠性智能化优化程序。为此，文中先扼要地介绍了传统遗传算法的基本原理及基于该方法的结构可靠性优化设计的基础理论，设计了一种改进的遗传算法。然后，编制了能分别处理连续变量和离散变量的优化程序，给出了基于遗传算法的桁架结构系统可靠性优化程序的功能、构成和框图，以及相应的算例及结果分析。通过算例的分析和比较，证明作者所采用的结构可靠性计算方法，对遗传算法的改进和开发的程序是有效的、可靠的，是解决大中型结构系统可靠性分析优化的一种较好途径。 本文最后对基于可靠性的结构智能化优化设计的研究进行了总结和展望，在前述基础上提出了进一步的工作。更多还原

【Abstract】 Probability-based intelligent optimum design of structural systems is a new subject in recent tens years. It considers structures as a whole, and studies the randomness of the structures in the future. It is more rational than the traditional way. Introducing some intelligent methods into the area of probabilistic optimum design is one of focuses of this field.First of all, the thesis introduces the progress of probability-based intelligent optimum design of structural systems and its analysis methods. Then it narrates the essential theory of the methods for reliability analysis of structural systems concisely and the methods in this thesis. The thesis, in the probability analysis and computation, considers the failure history of space frames and trusses, adopts the bound criterion and algorithms on the base of system’s critical strength, and introduces the soft self-adaptation control bound into the identification of dominant failure modes; at the same time, with the incremental load method and differential equalized recursive method, computes the limit-state function of failure mode and probability index precisely under no leaking the dominant failure modes. Programs are developed which are adaptable to the automatic reliability analysis of structural system. The thesis gives some calculating examples. It also studies some problems of reliability theory and algorithms, and presents some conclusions. It is tested that the method is effective.Because of the complexity of question and the limitation of traditional methods, computational intelligence is developed. Genetic algorithm (GA) is popularly used to settle the optimum problem. So the important work of the thesis is to develop a program for Probability-based intelligent optimum design of structural systems based on GA. Firstly, the thesis introduces the fundamental theory of GA and probabilistic optimum design, designs an advanced GA methods. Then programs a program to deal with the optimization, including continuous variables and disperse variables, introduces the function, structural and flow chart of the program, and gives some calculating examples and results’ analysis. Through the analysis and contrast on the examples, it proves that the methods of reliability computation, the improving of GA and program are reliable and efficient. It is a suitable new way to deal withprobabilistic analysis and optimum design of structural systems.Finally, probability-based intelligent optimum design of structural systems is summarized and expected, and next work is presented.更多还原